It is hard of course to play safe but you must think otherwise you are going to lose some money with it and that is bad.
Betting small amounts will have the same outcome as betting a large amount at once. Both of them can have an outcome that is either you lose all your money or you go home richer than before. But if you do have the control to stop whenever you're already losing the majority of your money, then betting small amounts is recommended to you.
Some people do not want to waste their time playing in front of their PC so they prefer doing large bets. It might not be safer than betting small amounts, but it's more fun doing that. And that is the essence of gambling IMO. Having a safe methods in gambling takes all the fun away. If you can't afford to lose your money, then don't gamble.
The smaller bets on the same game with another variation always wins?
Isn't that a strange observation too you?
I would prefer to having a safe way to bet than too have fun if you really want to know.